Due to my work requirements I have a Windows 7 laptop, so I don't have the choice of KVM. I have been using VMWare Player to run my linux development environment, but VMWare's UI consistently irritates me and I notice a fair amount of strange Zend/PHP segfaults.

Also, I like having a FreeBSD development environment for certain things, but VMWare player doesn't play well with FreeBSD in graphical mode. Something about event handling seems completely broken, because I can type several characters in any graphical application and they will not show up until I move the mouse--odd.

Thus I am trying out VirtualBox. So far it has done fine with FreeBSD in terminal mode... as a stress-test I am compiling the whole graphical environment, from Xorg to KDE, and it has handling things quite well. Here's hoping it will handle graphical apps well too. (Another plus about VirtualBox is you get Snapshots for free, which you don't get with the free VMWare Player.)